Analysis

It has been exhausting just to watch Oscar Pistorius - doubled up on the ropes for hour after hour, heavy arms trying to fend off another clinical combination of lethal jabs and low blows from prosecutor Gerrie Nel.

As the athlete finally slinks wearily back across the court from the witness stand to the dock, he must know that the last five days have done him few favours in this trial.

He has been forgetful, evasive, agitated, uncertain, argumentative, and defiantly - some would say deliberately - ambiguous about some of the key issues at the heart of this murder trial. However well his forensic experts proceed to shore up his testimony in the coming days, his credibility has been damaged.

I have been fending off emails from members of the public anxious to unearth some "smoking gun" detail that can resolve this case once and for all.

But the reality, from my vantage point in the public gallery here, is that there is no "smoking gun" - besides the obviously literal one.

The prosecution says he deliberately shot dead Ms Steenkamp, a 29-year-old model and law graduate, after the couple had had an argument.

He faces 25 years to life in prison if convicted of premeditated murder.

Mr Pistorius' defence lawyer Barry Roux presented to the court the Valentine card which Ms Steenkamp had got the athlete.

The double-amputee sprinter, 27, read it out in a trembling voice.

The front of the card reads: "Roses are red, violets are blue..."

Inside, she had written: "I think today is a good day to tell you that, I love you."

Ms Steenkamp was shot dead in the early hours of Valentine's Day - before they had opened each other's cards and gifts.

The athlete has previously told the court he only opened the card on Ms Steenkamp's birthday, in August 2013.

On the final day of his cross-examination, Mr Pistorius said that after shooting and realising Ms Steenkamp was not in the bedroom as he believed, he tried to break down the door with his shoulder, before using a cricket bat, all the time screaming in panic.

He said he stopped screaming when he finally opened the door and saw the body.

When the prosecutor asked why, he replied, his voice trembling with emotion: "I was heartbroken... overcome with sadness."

"I crouched down over her... and I checked to see if she was breathing or if she had a pulse," he said.

But this was disputed by prosecutor Gerrie Nel.

"You fired four shots through the door whilst knowing that she was standing behind the door," he said.

"She was locked into the bathroom and you armed yourself with the sole purpose of shooting and killing her."

Mr Pistorius replied: "That is not true."

The athlete has previously said he and Ms Steenkamp had spent a quiet evening together before he woke up on hearing a noise in the bathroom.

During the cross-examination, Mr Pistorius broke down in tears on several occasions.

Mr Nel suggested that he was doing this on purpose when he was struggling to explain his actions.

Mr Pistorius has now ended his testimony.

Oscar Pistorius returned to the dock after ending his testimony

The court has been shown the toilet door through which Mr Pistorius shot Ms Steenkamp

Forensic expert Roger Dixon was the next defence witness.

He told the court that with the light out, the room would have been almost completely dark, despite a couple of LED lights.

This supports Mr Pistorius' evidence that he did not see if Ms Steenkamp was still in bed when he got up.

The court also heard sound recordings Mr Dixon had made - of a cricket bat striking a door similar to that in Mr Pistorius' toilet, and another of gunshots fired through same door.

Mr Dixon seemed to struggle to tell the sounds apart, which the BBC's Pumza Fihlani in Pretoria says the defence will use to cast doubt on what neighbours say they heard that night.

Prosecution witnesses have testified to hearing a woman scream followed by gun shots, but the defence disputes their testimony, saying the only scream came from Mr Pistorius - after he had fired.

Both prosecution and defence have asked the judge to postpone the case after Thursday's hearings until 5 May.

Mr Nel said members of his team were engaged in "more pressing" cases, which needed their attention, as well as "personal arrangements" over the Easter holidays.

The defence said the case should still finish on 16 May, as planned. The judge said she would deliver her judgement on this request on Wednesday.

Oscar Pistorius and Reeva Steenkamp had been dating for three months

If Mr Pistorius is acquitted of murder, the court must consider an alternative charge of culpable homicide, for which he could receive about 15 years in prison.

He also faces charges of illegally firing a gun in public and of illegally possessing ammunition, both of which he denies.

There are no juries at trials in South Africa, and his fate will be decided by the judge, assisted by two assessors.

Mr Pistorius is known as the "Blade Runner" because of the carbon-fibre prosthetics he uses on the track.

1. Balcony

Mr Pistorius said in his statement at the start of the trial that he woke in the early hours and walked on his stumps to the balcony, pulled in two fans, closed the sliding door and drew curtains. He said that shortly before he had spoken to Reeva, who was in bed beside him.

He said he rejected prosecution claims that a witness heard arguing coming from the house before the shooting.

4. Bedroom

Mr Pistorius said he went back to the bedroom after shooting at the toilet door, still shouting for Reeva. Lifting himself up onto the bed, he felt over to the right hand side of it and noticed Ms Steenkamp was not there.

Mr Pistorius said this was when he realised she could have been in the toilet.

5. Toilet door

Mr Pistorius said he went back to the bathroom but the toilet was locked, so he returned to the bedroom, pulled on his prosthetic legs, turned on the lights before bashing in the toilet door with a cricket bat.

Forensics expert Johannes Vermeulen told the court that the height of the marks on the door caused by the cricket bat suggest Mr Pistorius was on his stumps at the time.

6. Emergency calls

Mr Pistorius's defence team say he then called security at the gated housing complex and a private paramedic service before carrying Ms Steenkamp downstairs.

A security guard claimed it was the other way round, and he had called Mr Pistorius first after reports of gunfire. However, phone records shown to the court revealed Mr Pistorius called the estate manager at 3:19am, a minute later he called the ambulance service and at 3:21am he called estate security.

A minute later he received an incoming call - estate security calling him back.

According to police phone expert Francois Moller, Mr Pistorius called his friend Justin Divaris a short time later and just after 4:00am he called his brother Carl.